1. Field of the Invention
This invention relates to electrophotographic photosensitive members and more particularly to an electrophotographic photosensitive member containing a specific azo pigment having photoconductivity.
2. Description of the Prior Art
Inorganic photoconductive materials such as, selenium, cadmium sulfide, zinc oxide, etc. have so far been widely used for electrophotographic photosensitive members.
On the other hand, various organic photoconductive materials for use in electrophotographic photosensitive members are known, including photoconductive polymers, a typical example thereof being poly(N-vinylcarbazole), low molecular weight organic photoconductive materials such as 2,5-bis(p-diethylaminophenyl)-1,3,4-oxadiazole, and further combinations of such organic photoconductive materials with various types of dyes or pigments.
Organic photoconductive materials, because of their good film forming property, can be used by simple coating for producing electrophotographic photosensitive members with much high productivity, thus giving inexpensive photosensitive members. Further, color sensitivity of organic photoconductive material-containing photosensitive members can be freely controlled by selection of the sensitizer to be used from a wide variety of dyes and pigments. Having such advantages, organic photoconductive materials have been inverstigated extensively. However, photosensitive members employing organic photoconductive materials are disadvantageous in sensitivity and durability, so that a very few of them have been put into practical use.